Change the return type of WTF::bind() to |OwnPtr<Function>|

Source/platform/Task.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 15 matching lines @@
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef Task_h
 #define Task_h
 
 #include "public/platform/WebThread.h"
 #include "wtf/Functional.h"
+#include "wtf/OwnPtr.h"
+#include "wtf/PassOwnPtr.h"
 
 namespace blink {
 
 class Task : public WebThread::Task {
 public:
-    explicit Task(const Closure& closure)
+    explicit Task(PassOwnPtr<Closure> closure)
         : m_closure(closure)
     {
     }
 
     virtual void run() override
     {
-        m_closure();
+        (*m_closure)();
     }
 
 private:
-    Closure m_closure;
+    OwnPtr<Closure> m_closure;
 };
 
 } // namespace blink
 
 #endif // Task_h